First of all, there are no guarantees with this one. However, almost always, if your regular drive works and you put in a new drive as a slave, you can download and run a program called
XXClone (follow instructions carefully to make it bootable), and it will make an exact image of the drive you are copying from. Then, remove the old drive and the new one (make it a master) should function normally with no loss of data. For best results, if the old drive is an IDE, then I suggest you get another IDE drive to clone to. The nice thing about this, is that you can try it and if you have a failure or it does not work, then you still have the original to boot from so you can try again.